Abstract:
Apparatus is disclosed herein for extending the length of a trailing wave of a double sided laminar wave of solder by the use of a dam in an oil intermix wave soldering system to create a dead zone while still being able to remove oil from the surface of the dead zone area on a continuous basis to prevent contaminants from interfering with soldering operations.
Abstract:
Solder is forced through an ejector and flow well to impinge a solder fountain against soldered leads extending through a circuit board from a component. The solder on the leads is melted to permit the removal and replacement of the component. Overflowing solder is collected and recirculated by action of the ejector. The construction of the solder fountain is such that there are no close fitting moving parts which may become clogged by solder inclusions.
Abstract:
For use in soldering the backplanes of printed circuit or other type electronic boards, a solder wave generator is disclosed with opposed side jet walls. The side jet configuration, because of opposed jet flow, provides an inertia necessary to balance the side forces and the pressure developed by the central pool of fluid, in this instance solder. The central pool, as supported by the side flow, is nearly stationary and the width of the pool can be varied substantially without increasing the total flow rate or the head of the pumping system.
Abstract:
Workpieces, such as printed circuit boards, are processed by passing the boards in contact with a standing wave of molten solder formed by circulating molten solder upwardly through a nozzle to overflow at least one edge thereof to form a standing wave which is accelerated by gravity so as normally to have an upper surface ballistically curved in the direction of flow. In accordance with the invention, the undersurface of the standing wave is supported to have a ballistic curvature, in the direction of flow, such that a major portion of the upper surface of the wave is substantially planar with the cross-sectional area of the wave varying, in the direction of flow, in a manner similar to the variation of the cross-sectional area of an unsupported wave following a ballistic curve in is trajectory. This results in the upper surface of the wave being substantially planar throughout a major portion of its length, and inclined downwardly from the horizontal, at a small angle, in the direction of flow of the solder. The angle to the horizontal may be varied between 3.degree.-10.degree. but preferably is from 4.degree. to 6.degree.. Supporting of the undersurface of the wave is effected by an extension of at least one wall of the nozzle, in the direction of solder flow, this extendsion having a ballistic curvature in the direction of solder flow of an extent such that the upper surface of the standing wave is substantially flat and inclined downwardly in the direction of the flow.
Abstract:
An improved method for soldering the terminals of a rigid printed circuit board to those of a flexible printed circuit board, such method comprising the steps of focusing a radiant heating source upon each of a plurality of solder globules deposited in a like number of through holes in the terminals of the rigid printed circuit board for controlling of the capillary flow of the molten solder radially from the through holes to form solder points of controlled depth and pattern between the terminals of the boards.
Abstract:
Removal of excess or undesirable solder from printed circuit boards that may contain through-holes, conductors, connectors, etc. is accomplished by covering such boards with liquid flux, contacting with liquid solder, removing from the solder, and subsequently passing intermediate offset, hot gas jets which flow hot gas under pressure onto the boards and sweep off undesired solder, clear the holes, and leave an optimum thickness solder layer.
Abstract:
The wave soldering apparatus of present disclosure includes a sump for receipt of a predetermined level of molten solder and having a driveshaft-receiving opening in the bottom wall thereof. A fountain is disposed in such sump and is formed with a chamber that leads upwardly above the predetermined level and terminates in a horizontally disposed outlet orifice. Molten solder is pumped into the lower portion of such fountain by pump means which includes an impeller having a driveshaft projecting therefrom and through the driveshaft-receiving opening. Barrier means surrounds such driveshaft means to block molten solder from coming into contact therewith and leaking out through the driveshaft-receiving opening.
Abstract:
Homogenization of petroleum oil in molten solder is produced in stages in an agitation chamber formed about the outlet of a solder pump of a standing wave soldering machine. In the first stage, a high pressure stream of oil is directed at the pressure faces of the pump propeller blades to produce intermittent counteracting forces creating turbulence which reduces the oil to small particles and distributing them in the oppositely moving stream of molten solder. In the second stage, droplets or globules of oil remaining in the stream of oil and molten solder separate rising to the top of the agitation chamber to be drawn through an impeller agitator which completes the reduction of the oil globules to finely divided particles which are distributed uniformly throughout the surrounding molten solder by shearing action of the agitator. The homogenized mixture of oil and molten solder flows into a pressure tank of the soldering machine to produce a standing wave of solder at a duct orifice.
Abstract:
A method of securing at least one multilead electronic component upon a supporting medium in an electrically correct manner, involving the leads of the component to a large extent disposed on the same side of the supporting medium or board as the component, with the component itself being passed through molten solder during the soldering of the component leads to the circuitry of the supporting medium. Because the necessity of through holes in the supporting medium is thus essentially eliminated, the practice of my method can result in the manufacture of circuit boards having an extremely high component density, with this method also making possible the use of wave solder techniques, and therefore the production of high density circuit boards and the like in a very rapid manner. A novel circuit board is also taught herein, involving at least one multilead component placed on a supporting medium with its lead terminations to a large extent located on the same side of the supporting medium as the component itself. Single sided as well as double sided boards of high density can be made in this manner.
Abstract:
A radiant energy transmissive member, such as of quartz, is formed with a plurality of peculiarly contoured grooves therein to accommodate, align and facilitate the simultaneous reflow soldering of a plurality of wires or leads to aligned and preferably solder-coated elements, such as circuit path extremities on a printed circuit board. Each groove is contoured such that the solder confined therein, when heated to a molten state, will be drawn at least in part by capillary attraction over the top of the associated wire or lead, with the solder merging on either side with the adjacent element so as to form a reliable fillet-shaped reflow solder connection. Also, by masking one surface of the quartz member so as to be selectively opaque, the radiant energy can be directed more precisely in accordance with a resultant transparent pattern only specific areas to be heated.